A screening method for detecting defects in LED packages

Abstract

The present application relates to the technical field of LED package defect detection, and particularly relates to a screening method for detecting LED package defects, which comprises the following steps: determining the panel position of an LED package by electrifying, and arranging a light intensity sensing panel; obtaining the light intensity data of each position of the light intensity sensing panel corresponding to the time sequence process under a set voltage; determining the light intensity defect position of the LED package; adjusting the angle between the light intensity sensing panel and the panel of the LED package to determine the light intensity dead point area of the LED package; adjusting the angle again and reducing the electrifying voltage of the LED package to determine the light intensity dead point area of the LED package based on the maximum difference between the adjusted light intensity data and the average light intensity data; and screening the LED package. The present application realizes accurate positioning of the defects of the LED package and selective and accurate screening of the LED package.

Description

Technical Field

[0001] The present invention relates to the technical field of LED package defect detection, and in particular to a screening method for detecting LED package defects. Background Art

[0002] LED is the English abbreviation of semiconductor light-emitting diode. LED packaging refers to the packaging of light-emitting chips. Compared with integrated circuit packaging, LED packaging is quite different. It is required not only to protect the wick but also to be light-transmitting to improve the stability of the chip. A good LED package can make the LED have better luminous efficiency and heat dissipation environment, thereby improving the service life and performance of the LED. Therefore, it is necessary to accurately screen the LED to ensure the quality of the processed LED.

[0003] Chinese Patent Publication No.: CN116977340B discloses a method for detecting defects in LED semiconductor packaging glue based on optical information. This method uses information from X-ray images obtained by optical means to obtain internal density information of the glue, and information from visible light surface images to obtain morphological information of the glue surface. The difference between morphological information and density information is used to perform primary enhancement on defect features, and the difference in area of ​​connected domains in the two images is used for secondary enhancement, so that the features of the packaging glue bubble defect area are more obvious. The packaging glue bubble defect area can be identified simply and quickly. It can be seen that the LED packaging defect detection method, device and system have the following problems: the detection method is a static image detection method, which cannot accurately locate the defects of the LED package and cannot adjust the screening criteria accordingly according to actual conditions to achieve selective and accurate screening of the LED package. Summary of the Invention

[0004] To this end, the present invention provides a screening method for detecting LED package defects to overcome the problems in the prior art of being unable to accurately locate LED package defects and being unable to adjust the screening criteria accordingly according to actual conditions to achieve selective and accurate screening of LED packages.

[0005] To achieve the above objectives, the present invention provides a screening method for detecting LED package defects, comprising:

[0006] Step S1, powering on the LED package and determining the panel position of the LED package;

[0007] Step S2, placing a light intensity sensing panel at a position that is an orthographic projection of the panel of the LED package, wherein the light intensity sensing panel is provided with an angle adjustment mechanism to adjust the angle between the light intensity sensing panel and the panel of the LED package, and the light intensity sensing panel is provided with a plurality of light intensity sensors to obtain light intensity data after the LED package is powered on;

[0008] Step S3, after the LED package is powered on, obtaining light intensity data corresponding to each position of the light intensity sensor panel during a time sequence under a set voltage, and determining the position of the light intensity defect of the LED package according to each light intensity data;

[0009] Step S4, adjusting the angle between the light intensity sensing panel and the panel of the LED package based on the range corresponding to the light intensity defect position and the light intensity data;

[0010] Step S5, determining the light intensity bad point area of ​​the LED package based on the light intensity data corresponding to each light intensity defect position after the angle adjustment;

[0011] Step S6, adjusting the angle between the light intensity sensing panel and the panel of the LED package again according to the distribution of the light intensity bad spot area, and reducing the power supply voltage of the LED package, and determining the light intensity bad spot area of ​​the LED package based on the maximum difference between the light intensity data corresponding to each light intensity bad spot area after the angle adjustment and the average light intensity data;

[0012] Step S7, screening the LED packages based on the adjusted angle between the light intensity sensing panel and the panel of the LED package, the power-on time of the panel of the LED package, the maximum difference and the area of ​​the light intensity bad point.

[0013] Furthermore, in the step S2, the light intensity sensors of the light intensity sensing panel are arranged in an array, and the area of ​​the arrangement of the light intensity sensors of the light intensity sensing panel is larger than the panel area of ​​the LED package.

[0014] Furthermore, in step S2, the angle between the light intensity sensing panel and the panel of the LED package is adjusted by controlling the angle adjustment mechanism so that the area of ​​the direct light of the LED package obtained on the light intensity sensing panel satisfies the requirement that the ratio of the direct light projection area obtained on the light intensity sensing panel to the direct light projection area obtained on the light intensity sensing panel at the orthographic projection angle after the angle adjustment is greater than a preset ratio;

[0015] The preset ratio is determined according to the area of ​​the light intensity defect position.

[0016] Furthermore, in step S3, determining the position of the light intensity defect of the LED package includes:

[0017] Determine the light intensity defect position of the LED package according to a comparison result between the light intensity data corresponding to each position of the light intensity sensor panel under the set voltage and the preset first light intensity at a single monitoring time point;

[0018] According to the set voltage, the energized time length of the light intensity data of each position of the light intensity sensing panel reaching the preset first light intensity determines the light intensity defect position of the LED package.

[0019] The set voltage is determined according to the panel standard operating voltage of the LED package.

[0020] Further, in the step S3, if the difference between the light intensity data of any position on the light intensity sensing panel and the preset first light intensity is greater than the first standard light intensity difference, the panel area of the LED package corresponding to the light intensity data is determined as the light intensity defect position.

[0021] Further, in the step S3, the panel of the LED package is energized, and the light intensity data of each position of the light intensity sensing panel is continuously acquired until the energized time length reaching the preset first light intensity, and the light intensity defect position of the LED package is determined according to the comparison result of the energized time length and the preset energized time length. If the energized time length is greater than the preset energized time length, the panel area of the LED package corresponding to the time length is determined as the light intensity defect position.

[0022] Further, in the step S4, the adjustment of the angle of the light intensity sensing panel and the panel of the LED package is determined according to the area ratio of the panel of the LED package corresponding to the light intensity defect position to the total area of the panel of the LED package, the light intensity data corresponding to each light intensity defect position, and the concentration of each light intensity defect position.

[0023] Further, in the step S5, the light intensity defect area of the LED package is determined based on the comparison result of the light intensity data corresponding to each light intensity defect position after the angle adjustment and the preset second light intensity.

[0024] If the light intensity data corresponding to each light intensity defect position after the angle adjustment is less than the preset second light intensity, the panel area of the LED package corresponding to the light intensity data after the angle adjustment is determined as the light intensity defect area.

[0025] Further, in the step S6, the average light intensity data is the average light intensity of all light intensity data of the light intensity defect area detected by the light intensity sensing panel after the adjustment; whether the area of the light intensity defect area is included in the defect area is determined according to the maximum gap and the preset maximum gap threshold, and the light intensity defect area is calculated according to the defect area.

[0026] Furthermore, in step S7, a defect screening value is calculated based on each of the maximum gaps, the area of ​​the light intensity bad spot, the angle adjustment value between the light intensity sensing panel and the panel of the LED package, the light intensity difference values ​​before the angle adjustment, the light intensity difference values ​​after the angle adjustment and the power-on time, and the LED package is screened according to the defect screening value.

[0027] Compared with the prior art, the beneficial effect of the present invention lies in that the screening method for detecting LED package defects of the present invention increases the projection area by adjusting the angle between the light intensity sensing panel and the panel of the LED package, thereby exposing and capturing the bad pixels in the light intensity defect position, avoiding the inability to accurately locate the bad pixels due to the aggregation of bad pixels, and realizing the precise positioning of the light intensity bad pixel area; and by reducing the power-on voltage and acquiring each of the light intensity data during the power-on timing process, avoiding the omission of defects existing in the light intensity bad pixel area when the stable current is not reached during the power-on process, ensuring the integrity of the light intensity data, so as to realize the subsequent accurate capture of the light intensity bad pixel area, thereby improving the accuracy of the present invention in screening and defect positioning of the LED package; the defect screening value is calculated based on the adjusted angle, the power-on time, the maximum gap and the light intensity bad pixel area, so as to realize comprehensive analysis and judgment of the packaged LED, further improve and supplement the defect judgment of the LED package of the present invention, and improve the accuracy of the screening of the LED package.

[0028] Furthermore, the present invention achieves uniform acquisition of the light intensity data in each area through the array arrangement of each light intensity sensor, so that the light intensity data can be analyzed more accurately later; by setting the area of ​​the light intensity sensing panel to be larger than the panel area of ​​the LED package, the omission of the light intensity data and bad points is avoided, and the integrity of the light intensity data is ensured, so that the light intensity defect position and the light intensity bad point area can be accurately analyzed later, thereby improving the accuracy of the present invention in screening and defect positioning of the LED package.

[0029] Furthermore, the present invention increases the projection area by adjusting the angle between the light intensity sensing panel and the panel of the LED package, thereby exposing and capturing the bad pixels in the light intensity defect position, avoiding the inability to accurately locate the bad pixels due to the aggregation of bad pixels, and achieving precise positioning of the light intensity bad pixel area, thereby improving the accuracy of the present invention in screening and defect positioning of the LED package.

[0030] Furthermore, the present invention avoids missing defects in the LED package in the bad point area when the stable current is not reached during the power-on process by capturing the light intensity data in the timing process, thereby achieving accurate capture of bad points and acquisition of light intensity data to determine the position of the light intensity defect, thereby improving the accuracy of screening and defect positioning of the LED package.

[0031] Furthermore, the present invention is configured to determine the difference between the light intensity data and the preset first light intensity and the difference between the first standard light intensity, and to limit the preset first light intensity according to actual conditions, so as to screen the light intensity data that conforms to actual conditions, thereby adjusting the screening criteria accordingly according to actual conditions, and achieving accurate and selective capture of the light intensity defect position, thereby ensuring the accuracy and flexibility of the light intensity data and the subsequent screening and defect positioning of the LED package.

[0032] Furthermore, the present invention powers on the panel of the LED package and continuously obtains light intensity data at each position of the light intensity sensing panel until the power-on time reaches the preset first light intensity and compares it with the preset power-on time, thereby further judging the light intensity defect position and screening the light intensity data that does not reach the preset first light intensity, thereby avoiding the omission of the light intensity defect position where the light intensity data reaches the preset first light intensity but the power-on time is insufficient, and by continuously obtaining the light intensity data, the accuracy and completeness of the light intensity data are guaranteed, so as to perform subsequent calculations of the average light intensity and the area of ​​the bad pixel region, thereby improving the accuracy of the present invention in screening and defect positioning of the LED package.

[0033] Furthermore, the present invention determines the adjustment angle according to the ratio of the area of ​​the panel of the LED package corresponding to the light intensity defect position to the total area of ​​the panel of the LED package, the light intensity data corresponding to each light intensity defect position and the concentration of each light intensity defect position, thereby realizing control over the angle adjustment, avoiding the concentration of the light intensity defect position and the light intensity bad point area due to too small an adjustment angle, and failing to accurately locate and capture the bad point, thereby realizing the accuracy of locating and capturing the light intensity bad point area and the defect, thereby improving the accuracy of the present invention in screening and locating defects of the LED package.

[0034] Furthermore, the present invention exposes and captures the bad spots in the light intensity defect positions through the angle adjustment to further obtain the light intensity data for the light intensity defect positions, thereby avoiding the concentration of the light intensity defect positions and the light intensity bad spot area due to the total area ratio being too small, the light intensity data corresponding to each light intensity defect position being too small, or the concentration being too large, and the inability to accurately locate the bad spots, further improving the accuracy of the acquired light intensity data and the accuracy of determining the light intensity bad spot area, thereby improving the accuracy of the present invention in screening and defect positioning of the LED package.

[0035] Furthermore, the present invention determines a preset maximum gap threshold according to actual conditions, and determines whether the area of ​​the light intensity bad point area is included in the bad point area by comparing the maximum gap with the preset maximum gap threshold, thereby excluding the light intensity data and light intensity bad point areas whose maximum gap is less than or equal to the preset maximum gap threshold, further refining the light intensity bad point area, thereby improving the flexibility of the present invention in screening the LED packages.

[0036] Furthermore, the present invention calculates defect screening values ​​based on the maximum gap, the area of ​​the light intensity bad point, the angle adjustment of the panel of the LED package, the light intensity differences before the angle adjustment, the light intensity differences after the angle adjustment and the power-on time, thereby achieving comprehensive analysis and judgment of the packaged LED, further improving and supplementing the present invention's defect judgment on the LED package, and improving the accuracy of the screening of the LED package; the defect screening value expresses the degree of defect of the LED package, and by comparing the defect screening value with the defect screening value preset according to actual conditions to make a comprehensive judgment on whether the LED package meets the defect index, the screening criteria are adjusted accordingly according to actual conditions, thereby improving the flexibility of screening defective LED packages and locating defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a flowchart of a screening method for detecting LED package defects according to an embodiment of the present invention;

[0038] Figure 2 This is a workflow diagram of step S3 according to an embodiment of the present invention;

[0039] Figure 3 This is a workflow diagram of step S5 according to an embodiment of the present invention;

[0040] Figure 4 A schematic diagram of the projection of direct light obtained on the light intensity sensing panel before adjusting the angle between the light intensity sensing panel and the panel of the LED package according to an embodiment of the present invention;

[0041] Figure 5 A schematic diagram of the projection of direct light obtained on the light intensity sensing panel after adjusting the angle between the light intensity sensing panel and the panel of the LED package according to an embodiment of the present invention;

[0042] In the figure: 1. LED package panel; 2. Light intensity sensor panel; 3. Direct light projection before angle adjustment; 4. Direct light projection after angle adjustment. DETAILED DESCRIPTION

[0043] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0044] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0045] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0046] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0047] See also Figure 1 , which is a workflow diagram of a screening method for detecting LED package defects according to an embodiment of the present invention; an embodiment of the present invention provides a screening method for detecting LED package defects, comprising:

[0048] Step S1, powering on the LED package and determining the position of the panel 1 of the LED package;

[0049] Step S2, arranging a light intensity sensing panel 2 at a position that is an orthographic projection of the panel 1 of the LED package, wherein the light intensity sensing panel 2 is provided with an angle adjustment mechanism to adjust the angle between the light intensity sensing panel 2 and the panel 1 of the LED package, and the light intensity sensing panel 2 is provided with a plurality of light intensity sensors to obtain light intensity data after the LED package is powered on;

[0050] Step S3, after the LED package is powered on, obtaining light intensity data corresponding to each position of the light intensity sensor panel 2 during a time sequence under a set voltage, and determining the light intensity defect position of the LED package according to each light intensity data;

[0051] Step S4, adjusting the angle between the light intensity sensing panel 2 and the LED package panel 1 based on the range corresponding to the light intensity defect position and the light intensity data;

[0052] Step S5, determining the light intensity bad point area of ​​the LED package based on the light intensity data corresponding to each light intensity defect position after the angle adjustment;

[0053] Step S6, adjusting the angle between the light intensity sensing panel 2 and the panel 1 of the LED package again according to the distribution of the light intensity bad point area, and reducing the power supply voltage of the LED package, and determining the light intensity bad point area of ​​the LED package based on the maximum difference between the light intensity data corresponding to each light intensity bad point area after the angle adjustment and the average light intensity data;

[0054] Step S7, screening the LED packages based on the adjusted angle between the light intensity sensing panel 2 and the panel 1 of the LED package, the power-on time of the panel 1 of the LED package, the maximum gap and the light intensity bad point area.

[0055] The screening method for detecting LED package defects of the present invention increases the projection area by adjusting the angle between the light intensity sensing panel and the panel of the LED package, thereby exposing and capturing the bad pixels in the light intensity defect position, avoiding the inability to accurately locate the bad pixels due to the aggregation of bad pixels, and realizing the precise positioning of the light intensity bad pixel area; and by reducing the power-on voltage and acquiring each of the light intensity data during the power-on sequence, avoiding the omission of defects existing in the light intensity bad pixel area when the stable current is not reached during the power-on process, ensuring the integrity of the light intensity data, so as to realize the subsequent accurate capture of the light intensity bad pixel area, thereby improving the accuracy of the present invention in screening and defect positioning of the LED package; the defect screening value is calculated based on the adjusted angle, the power-on time, the maximum gap and the light intensity bad pixel area, so as to realize comprehensive analysis and judgment of the packaged LED, further improve and supplement the defect judgment of the LED package of the present invention, and improve the accuracy of the screening of the LED package.

[0056] Specifically, in step S2, the light intensity sensors of the light intensity sensing panel 2 are arranged in an array, and the area of ​​the arrangement of the light intensity sensors of the light intensity sensing panel 2 is larger than the area of ​​the panel 1 of the LED package.

[0057] It can be understood that by arranging the light intensity sensing panel 2 at a position that is a positive projection of the panel 1 of the LED package, the light intensity sensing panel 2 is made parallel to the panel 1 of the LED package, and the first light intensity data detected by the light intensity sensing panel 2 is obtained to determine the position of the light intensity defect.

[0058] It can be understood that by evenly dividing the light intensity sensing panel 2 into several completely identical areas with the same number of LEDs in each area, and arranging a single light intensity sensor in a single area to generate a single first light intensity data, an array arrangement of the light intensity sensors is achieved, which is used to uniformly acquire and analyze the light intensity in each area, thereby ensuring the uniformity of the acquired light intensity data.

[0059] The area of ​​the LED package corresponds one-to-one with the area of ​​the light intensity sensing panel 2, the light intensity data, and the light intensity sensor, thereby improving the accuracy of determining the position of the light intensity defect.

[0060] In a specific embodiment, the light intensity sensing panel 2 is evenly divided into 16 areas, and a total of 16 light intensity sensors are provided to obtain first light intensity data of 16 corresponding positions.

[0061] It can be understood that by setting the area of ​​the light intensity sensing panel 2 to be larger than the panel area of ​​the LED package, the light intensity data is prevented from being unable to correspond to the light-emitting position of the LED package, thereby ensuring the accuracy of obtaining the light intensity data, so as to facilitate subsequent accurate analysis of the first light intensity and improve the accuracy of defect detection and screening of the LED package.

[0062] The present invention achieves uniform acquisition of the light intensity data in each area through the array arrangement of the light intensity sensors, so that the light intensity data can be analyzed more accurately later; by setting the area of ​​the light intensity sensing panel to be larger than the panel area of ​​the LED package, the omission of the light intensity data and bad points is avoided, and the integrity of the light intensity data is ensured, so that the light intensity defect position and the light intensity bad point area can be accurately analyzed later, thereby improving the accuracy of the present invention in screening and defect positioning of the LED package.

[0063] See also Figure 4 and Figure 5 As shown, Figure 4 This is a schematic diagram of the direct light projection obtained on the light intensity sensing panel 2 before adjusting the angle between the light intensity sensing panel 2 and the LED package panel 1 according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the direct light projection obtained on the light intensity sensing panel 2 after adjusting the angle between the light intensity sensing panel 2 and the LED package panel 1 according to an embodiment of the present invention.

[0064] Specifically, in step S2, the angle between the light intensity sensing panel 2 and the panel 1 of the LED package is adjusted by controlling the angle adjustment mechanism so that the area of ​​the direct light of the LED package obtained on the light intensity sensing panel 2 satisfies the requirement that, after the angle adjustment, the ratio of the direct light projection area obtained on the light intensity sensing panel 2 to the direct light projection area obtained on the light intensity sensing panel 2 at the orthographic projection angle is greater than a preset ratio;

[0065] The preset ratio is determined according to the area of ​​the light intensity defect position.

[0066] In implementation, the preset ratio is proportional to the ratio of the light intensity defect position to the panel area of ​​the LED package, and the preset ratio ranges from 1.5 to 3.

[0067] like Figure 4 and Figure 5 As shown, the projection area of ​​the direct light projection 4 after the angle adjustment is larger than the projection area of ​​the direct light projection 3 before the angle adjustment; when the ratio of the direct light projection area obtained on the light intensity sensing panel 2 to the direct light projection area obtained on the light intensity sensing panel 2 at the positive projection angle increases, the intensity data of the direct light obtained is more accurate, the omission of the direct light intensity is reduced, the accuracy of the intensity data is improved, and the accuracy of the subsequent defect detection and screening of the LED package is guaranteed.

[0068] It is understandable that the angle adjustment mechanism can be any mechanism in the prior art, which will not be described in detail here, as long as it can adjust the angle between the light intensity sensor panel 2 and the LED package panel 1.

[0069] It is understood that the angle adjustment mechanism can adjust the angle of the light intensity sensing panel 2 so that more sensors on the light intensity sensing panel 2 can obtain the direct light intensity on the LED package panel 1, thereby increasing the amount of light intensity data at the location of light intensity defects. It is understood that the rotation angle of the angle adjustment mechanism can be determined based on the ratio of the direct light projection area obtained on the light intensity sensing panel 2 after adjustment to the direct light projection area obtained on the light intensity sensing panel 2 at the orthographic projection angle. This can be directly calculated using trigonometric functions and will not be further described here.

[0070] It can be understood that the angle adjustment mechanism can freely set the adjustment angle and rotation direction of the light intensity sensing panel 2 or the panel 1 of the LED package. It only needs to ensure that the area of ​​the direct light of the LED package obtained on the light intensity sensing panel 2 satisfies the ratio of the direct light projection area obtained on the light intensity sensing panel 2 after the angle adjustment to the direct light projection area obtained on the light intensity sensing panel 2 at the positive projection angle is greater than the preset ratio.

[0071] The present invention increases the projection area by adjusting the angle between the light intensity sensing panel and the panel of the LED package, thereby exposing and capturing bad pixels in the light intensity defect position, avoiding the inability to accurately locate bad pixels due to the aggregation of bad pixels, and achieving precise positioning of the light intensity bad pixel area, thereby improving the accuracy of the present invention in screening and defect positioning of the LED package.

[0072] See also Figure 2 As shown, it is a workflow diagram of step S3 described in an embodiment of the present invention.

[0073] Specifically, in step S3, determining the position of the light intensity defect of the LED package includes:

[0074] Determine the light intensity defect position of the LED package according to the comparison result of the light intensity data corresponding to each position of the light intensity sensor panel 2 under the set voltage at a single monitoring time point and the preset first light intensity;

[0075] Determine the light intensity defect position of the LED package according to the power-on time length when the light intensity data corresponding to each position of the light intensity sensor panel 2 in the timing process reaches the preset first light intensity under the set voltage;

[0076] The set voltage is determined according to the standard operating voltage of the panel 1 of the LED package.

[0077] Preferably, in implementation, the position of the light intensity defect can be determined by any one of the following two detections, wherein:

[0078] The first determination method is to determine the light intensity defect position of the LED package based on the comparison result of the light intensity data corresponding to each position of the light intensity sensor panel 2 during the time sequence under each set voltage at a single monitoring time point and a preset first light intensity; the single monitoring time point here is selected as the stable light intensity data obtained by each sensor on the light intensity sensor panel 2 a period of time after the power is turned on as the judgment data;

[0079] The second determination method: determine the light intensity defect position of the LED package according to the time it takes for the light intensity data corresponding to each position of the light intensity sensor panel 2 in the timing process under each set voltage to reach the preset first light intensity; the set voltage here is generally selected from the rated operating voltage of the LED package, and the light intensity sensor panel 2 needs to obtain the timing light intensity data of the LED package after the power is turned on in real time, as judgment data for determining the time it takes to reach the preset first light intensity.

[0080] In this embodiment, the preset first light intensity is determined according to actual conditions, including the standard light intensity requirement of the LED package when it leaves the factory.

[0081] It can be understood that the light intensity data corresponds one-to-one to the position of the light intensity sensing panel 2 and the position of the light intensity defect.

[0082] The light intensity data is the light intensity data obtained at each position of the light intensity sensing panel 2 during the timing process at the single monitoring time point or the set voltage, and the light intensity data is compared with the preset first light intensity to determine the light intensity defect position of the LED package.

[0083] It is understood that the timing process is the process of energizing the LED package area from no current to a stable current, provided that the light intensity data reaches a predetermined first light intensity. The timing process includes a plurality of individual monitoring time points. The location of the light intensity defect in the LED package is determined by comparing the time during which the light intensity data reaches the predetermined first light intensity with the predetermined power-on duration.

[0084] The present invention avoids missing defects in the LED package in the bad point area when the stable current is not reached during the power-on process by capturing the light intensity data during the timing process, thereby achieving accurate capture of bad points and obtaining light intensity data to determine the position of the light intensity defect, thereby improving the accuracy of screening and defect positioning of the LED package.

[0085] Specifically, in step S3, if the difference between the light intensity data at any position on the light intensity sensing panel 2 and the preset first light intensity is greater than the first standard light intensity difference, the panel area of ​​the LED package corresponding to the light intensity data is determined as the light intensity defect position.

[0086] It can be understood that if the difference between the light intensity data at any position on the light intensity sensing panel 2 and the preset first light intensity is less than or equal to the first standard light intensity difference, the panel area of ​​the LED package corresponding to the light intensity data will be determined as a non-light intensity defect position, and no subsequent operation will be performed on the non-light intensity defect position.

[0087] It is understandable that the first standard light intensity difference is determined according to actual conditions, including the standard light intensity difference requirement of the LED package when it leaves the factory, and the difference between the light intensity data and the preset first light intensity is the absolute value of the difference.

[0088] The light intensity data is affected by actual conditions, including avoidable or unavoidable factors such as differences between produced LEDs, packaging quality, and instability of the current, which may lead to inconsistency between the light intensity data and the preset first light intensity.

[0089] When the difference between the light intensity data and the preset first light intensity is less than or equal to the first standard light intensity difference, the difference between the light intensity data and the preset first light intensity does not affect the normal use of the LED, and it is difficult to distinguish the differences between the light intensity values ​​from the appearance. Therefore, it can be judged as the non-light intensity defect position and no subsequent operation is performed, and the above-mentioned inconsistency in this case is ignored.

[0090] In this embodiment, if the difference between the first light intensity at any position on the light intensity sensing panel 2 and the preset first light intensity is greater than the first standard light intensity difference, the panel area of ​​the LED package corresponding to the first light intensity is determined as the light intensity defect position;

[0091] If the difference between the first light intensity at any position on the light intensity sensing panel 2 and the preset first light intensity is less than or equal to the first standard light intensity difference, the panel area of ​​the LED package corresponding to the first light intensity is determined as a non-light intensity defect position, and no subsequent operation is performed on the non-light intensity defect position.

[0092] In a specific embodiment, the light intensity data of a single LED is 0.7mcd, and the area of ​​a single light intensity sensing panel 2 has 16 LEDs. The preset first light intensity is 0.8mcd, then the difference between the first light intensity and the preset first light intensity is 0.7mcd-0.8mcd=-0.1mcd, and the first standard light intensity difference is 0.05mcd. 0.1mcd>0.05mcd, then the panel area of ​​the LED package corresponding to the defective area of ​​the light intensity sensing panel 2 is determined as the light intensity defect position.

[0093] The present invention sets a judgment on the difference between the light intensity data and the preset first light intensity and the difference between the first standard light intensity, and limits the preset first light intensity according to actual conditions, so as to screen the light intensity data that meets the actual conditions, realize corresponding adjustment of the screening criteria according to actual conditions, realize accurate and selective capture of the light intensity defect position, and ensure the accuracy and flexibility of the light intensity data and the subsequent screening and defect positioning of the LED package.

[0094] Specifically, in step S3, the panel 1 of the LED package is powered on, and after power-on, the light intensity data of each position of the light intensity sensing panel 2 is continuously obtained until the power-on time of the preset first light intensity is reached. The light intensity defect position of the LED package is determined based on the comparison result of the power-on time and the preset power-on time. If the power-on time is greater than the preset power-on time, the panel area of ​​the LED package corresponding to the time is determined as the light intensity defect position.

[0095] It can be understood that if the time length is less than or equal to the preset power-on time length, the panel area of the LED package corresponding to the time length is determined as a non-light intensity defect position, and no subsequent operation is performed on the non-light intensity defect position.

[0096] The preset power-on time length is the average of the power-on time lengths of each position of the panel area of the defect-free LED package in the historical detection after power-on, or is a standard time length when the LED package is shipped, and the extension of the power-on time length is caused by defects of the LED package, including short circuit, unstable voltage and current, resistance defects, etc. of the light intensity defect position LED.

[0097] The present application compares the power-on time length of the light intensity sensing panel of the LED package with the preset power-on time length by continuously obtaining the light intensity data of each position of the light intensity sensing panel after power-on until the preset first light intensity is reached, further judges the light intensity defect position, and screens the light intensity data that does not reach the preset first light intensity, thereby avoiding the omission of the light intensity defect position whose light intensity data reaches the preset first light intensity but the power-on time length is insufficient, and ensuring the accuracy and integrity of the light intensity data by continuously obtaining the light intensity data, so as to calculate the average light intensity and the area of the bad point area in the subsequent, thereby improving the accuracy of the screening and defect positioning of the LED package.

[0098] Specifically, in the step S4, the adjustment of the angle of the light intensity sensing panel 2 and the panel 1 of the LED package is determined according to the ratio of the area of the panel of the LED package corresponding to the light intensity defect position to the total area of the panel 1 of the LED package, the light intensity data corresponding to each light intensity defect position, and the concentration of each light intensity defect position.

[0099] It can be understood that if the ratio of the area of the panel of the LED package corresponding to the light intensity defect position to the total area of the panel 1 of the LED package is small, or the difference between the light intensity data corresponding to each light intensity defect position and the preset first light intensity is too small, or the concentration of each light intensity defect position is high, the number of defective LEDs cannot be determined and the light intensity bad point area of the LED package cannot be refined, it is determined to increase the angle of the light intensity sensing panel 2 and the panel 1 of the LED package, and the adjustment angle value is determined based on the total area ratio, the light intensity data and the concentration.

[0100] Preferably, if the area ratio of the LED packaging panel corresponding to the light intensity defect position to the total area of the LED packaging panel 1 is less than a ratio threshold, or the difference between the light intensity data corresponding to each light intensity defect position and the preset first light intensity is less than a difference threshold, or the concentration of each light intensity defect position is greater than a concentration threshold, it is determined that the angle between the light intensity sensing panel 2 and the LED packaging panel 1 needs to be adjusted, wherein the adjusted angle is greater than the adjusted angle.

[0101] It can be understood that the ratio threshold is determined according to the number N of sensors on the light intensity sensing panel 2, and is generally set to a value greater than or equal to 1 / N, the difference threshold can be set to the first standard light intensity difference, and the concentration of each light intensity defect position is determined according to the average distance between each non-adjacent light intensity defect position, and the concentration threshold is set to 8% to 13% of the length of the LED packaging.

[0102] The present application determines the adjusted angle according to the area ratio of the LED packaging panel corresponding to the light intensity defect position to the total area of the LED packaging panel, the light intensity data corresponding to each light intensity defect position, and the concentration of each light intensity defect position, realizes the control of the angle adjustment, avoids the concentration of the light intensity defect position and the light intensity dead point area due to the too small adjustment angle, and realizes the accuracy of the light intensity dead point area and the defect positioning and capturing, thereby improving the accuracy of the LED packaging screening and defect positioning of the present application.

[0103] Please refer to Figure 3 Fig. 5 is a workflow diagram of step S5 according to the embodiment of the present application.

[0104] Specifically, in step S5, the light intensity dead point area of the LED packaging is determined based on the comparison result of the light intensity data corresponding to each light intensity defect position after the angle adjustment and the preset second light intensity.

[0105] If the light intensity data corresponding to each light intensity defect position after the angle adjustment is less than the preset second light intensity, the panel area of the LED packaging corresponding to the light intensity data after the angle adjustment is determined as the light intensity dead point area.

[0106] It can be understood that if the light intensity data corresponding to each light intensity defect position after the angle adjustment is greater than or equal to the preset second light intensity, the panel area of the LED packaging corresponding to the light intensity data after the angle adjustment is determined as a non-light intensity dead point area, and no subsequent operation is performed on the non-light intensity defect position.

[0107] In the present embodiment, the preset second light intensity is set to 85% to 95% of the light intensity data obtained before the adjustment corresponding to the light intensity defect position.

[0108] The light intensity data after the angle adjustment corresponds one to one with the light intensity bad point area.

[0109] The light intensity data after the angle adjustment is affected by actual conditions, including avoidable or unavoidable factors such as differences between the produced LEDs, the quality of the packaging, and the instability of the power-on current, resulting in inconsistency between the light intensity data after the angle adjustment and the preset second light intensity.

[0110] When the light intensity data after the angle adjustment is greater than or equal to the preset second light intensity, the fluctuation of the detection value of the light intensity data after the angle adjustment does not affect the light intensity judgment of the LED before and after the angle adjustment. It is difficult to distinguish the difference in the light intensity values ​​after each angle adjustment from the appearance. Therefore, it can be judged as the non-light intensity bad point area and no subsequent operation is performed.

[0111] The present invention exposes and captures the bad spots in the light intensity defect positions through the angle adjustment, so as to further obtain the light intensity data for the light intensity defect positions, thereby avoiding the concentration of the light intensity defect positions and the light intensity bad spot areas due to the total area ratio being too small, the light intensity data corresponding to each light intensity defect position being too small, or the concentration being too large, and thus failing to accurately locate the bad spots. This further improves the accuracy of the acquired light intensity data and the accuracy of determining the light intensity bad spot areas, thereby improving the accuracy of the present invention in screening and defect positioning of the LED package.

[0112] Specifically, in step S6, the average light intensity data is the average light intensity of all light intensity data of the light intensity bad point area detected by the light intensity sensing panel 2 after adjustment; based on the maximum gap and the preset maximum gap threshold, it is determined whether the area of ​​the light intensity bad point area is included in the bad point area, and the light intensity bad point area is calculated based on the bad point area.

[0113] It can be understood that the preset maximum gap threshold is generally set to 5% to 10% of the average light intensity data. By comparing the maximum gap with the preset maximum gap threshold, it is determined whether the area of ​​the light intensity bad point area is included in the bad point area.

[0114] If the maximum difference is greater than a preset maximum difference threshold, the area of ​​the light intensity bad pixel region is counted as the bad pixel region area;

[0115] If the maximum difference is less than or equal to the preset maximum difference threshold, the area of ​​the light intensity bad pixel area is not counted into the bad pixel area.

[0116] By determining the maximum difference threshold to influence the determination of the light intensity bad spot area, the LED package can be screened according to actual conditions.

[0117] It can be understood that in step S7, by reducing the power-on voltage of the LED package and thereby reducing the current of the LED package to change the light intensity of the LED package, the exposure of the LED with packaging defects is improved, making it easier and more accurate to identify the LED with packaging defects, thereby improving the efficiency and accuracy of determining the area of ​​the light intensity bad point, and thereby improving the efficiency and accuracy of defect detection and screening of the LED package.

[0118] It can be understood that the monitoring time points are the time points when the light intensity sensor obtains light intensity data at each position of the light intensity sensing panel 2 according to a time sequence process under the adjusted set voltage.

[0119] The present invention determines a preset maximum gap threshold according to actual conditions, and determines whether the area of ​​the light intensity bad point area is included in the bad point area by comparing the maximum gap with the preset maximum gap threshold, thereby excluding light intensity data and light intensity bad point areas whose maximum gap is less than or equal to the preset maximum gap threshold, further refining the light intensity bad point area, thereby improving the flexibility of the present invention in screening the LED packages.

[0120] Specifically, in step S7, a defect screening value is calculated based on each of the maximum gaps, the area of ​​the light intensity bad spot, the angle adjustment between the light intensity sensing panel and the panel 1 of the LED package, the light intensity differences before the angle adjustment, the light intensity differences after the angle adjustment and the power-on time, and the LED package is screened according to the defect screening value.

[0121] In a specific embodiment, the defect screening value is determined by the following formula:

[0122]

[0123] Wherein, X is the defect screening value, a, b, c, d, e, and f are all constants, S is the light intensity bad point area, and S0 is the panel area of ​​the LED package. The angle values ​​of the light intensity sensor panel 2 are finally adjusted, H1, H2...H m is the maximum difference between the two, Y1, Y2, ..., Y n is the difference between the light intensity data on the light intensity sensor panel 2 corresponding to the light intensity defect position determined before the angle adjustment and the preset first light intensity, Y0 is the average light intensity of all light intensity data on the light intensity sensor panel 2 corresponding to the light intensity defect position determined before the angle adjustment, Z1, Z2...Z ma difference value between the light intensity data of each light intensity defect position corresponding to the light intensity bad point area determined after the angle adjustment and the preset second light intensity, Z0 is an average light intensity of all light intensity data of the light intensity bad point area detected by the light intensity sensing panel 2 after the angle adjustment, t1, t2, …, t n each of the power-on time lengths, t0 is the preset power-on time length, n is the total number of the light intensity data on the light intensity sensing panel 2 corresponding to the light intensity defect positions determined before the angle adjustment, m is the total number of each light intensity defect position corresponding to the light intensity bad point area determined after the angle adjustment, and m < n < the total number of the light intensity data on the light intensity sensing panel 2.

[0124] In another embodiment, a person skilled in the art can assign different evaluation scores to each data based on each of the maximum difference, the light intensity bad point area, the angle adjustment of the panel 1 of the LED package, each light intensity difference before the angle adjustment, each light intensity difference after the angle adjustment, and each of the power-on time lengths, and calculate a defect screening value according to the cumulative score.

[0125] It can be understood that the defect screening value is used to represent the defect degree of the LED package, and by comparing the defect screening value with a preset defect screening value, it is determined whether the LED package meets the defect screening requirement, so as to screen out the defective LED package.

[0126] It can be understood that the preset defect screening value is determined according to actual conditions, including the requirements for defect screening according to actual production, actual requirements for defect screening values in actual application scenarios, etc.

[0127] It can be understood that the expression of the defect screening value protected by the present application is not limited to the above expression, and any expression of several of the maximum difference, the light intensity bad point area, the angle adjustment value of the panel 1 of the LED package, each light intensity difference before the angle adjustment, each light intensity difference after the angle adjustment, and each of the power-on time lengths is positively correlated with the defect screening value.

[0128] The present application calculates a defect screening value based on the maximum difference, the light intensity bad point area, the angle adjustment of the panel of the LED package, each light intensity difference before the angle adjustment, each light intensity difference after the angle adjustment, and each of the power-on time lengths, realizes comprehensive analysis and judgment of the packaged LED, further perfects and supplements the defect judgment of the LED package, and improves the accuracy of screening the LED package; the defect screening value represents the defect degree of the LED package, and by comparing the defect screening value with the defect screening value preset according to actual conditions, a comprehensive judgment is made on whether the LED package meets the defect index, the screening standard is adjusted accordingly according to actual conditions, and the flexibility of screening the defective LED package and positioning the defect is improved.

[0129] The present application is not described in the prior art.

[0130] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after these changes or replacements will all fall within the protection scope of the present application.

Claims

1. A screening method for detecting LED package defects, characterized in that: include: Step S1, powering on the LED package and determining the panel position of the LED package; Step S2, placing a light intensity sensing panel at a position that is an orthographic projection of the panel of the LED package, wherein the light intensity sensing panel is provided with an angle adjustment mechanism to adjust the angle between the light intensity sensing panel and the panel of the LED package, and the light intensity sensing panel is provided with a plurality of light intensity sensors to obtain light intensity data after the LED package is powered on; Step S3, after the LED package is powered on, obtaining light intensity data corresponding to each position of the light intensity sensor panel during a time sequence under a set voltage, and determining the position of the light intensity defect of the LED package according to each light intensity data; Step S4, adjusting the angle between the light intensity sensing panel and the panel of the LED package based on the range corresponding to the light intensity defect position and the light intensity data; Step S5, determining the light intensity bad point area of ​​the LED package based on the light intensity data corresponding to each light intensity defect position after the angle adjustment; Step S6, adjusting the angle between the light intensity sensing panel and the panel of the LED package again according to the distribution of the light intensity bad spot area, and reducing the power supply voltage of the LED package, and determining the light intensity bad spot area of ​​the LED package based on the maximum difference between the light intensity data corresponding to each light intensity bad spot area after the angle adjustment and the average light intensity data; Step S7, screening the LED packages based on the adjusted angle between the light intensity sensing panel and the panel of the LED package, the power-on time of the panel of the LED package, the maximum difference and the area of ​​the light intensity bad point.

2. The method for detecting LED package defects according to claim 1, wherein: In the step S2, the light intensity sensors of the light intensity sensing panel are arranged in an array, and the area of ​​the arrangement of the light intensity sensor arrays is larger than the panel area of ​​the LED package.

3. The method for detecting LED package defects according to claim 1 or 2, wherein: In step S2, the angle between the light intensity sensing panel and the panel of the LED package is adjusted by controlling the angle adjustment mechanism so that the area of ​​the direct light of the LED package obtained on the light intensity sensing panel satisfies the requirement that the ratio of the direct light projection area obtained on the light intensity sensing panel to the direct light projection area obtained on the light intensity sensing panel at the orthographic projection angle after the angle adjustment is greater than a preset ratio; The preset ratio is determined according to the area of ​​the light intensity defect position.

4. The method for detecting LED package defects according to claim 3, wherein: In step S3, determining the position of the light intensity defect of the LED package includes: Determine the light intensity defect position of the LED package according to a comparison result between the light intensity data corresponding to each position of the light intensity sensor panel under the set voltage and the preset first light intensity at a single monitoring time point; Determine the light intensity defect position of the LED package according to the power-on time length during which the light intensity data corresponding to each position of the light intensity sensor panel reaches a preset first light intensity under the set voltage; The set voltage is determined according to the standard operating voltage of the panel of the LED package.

5. The method for detecting LED package defects according to claim 4, wherein: In step S3, if the difference between the light intensity data at any position on the light intensity sensing panel and the preset first light intensity is greater than the first standard light intensity difference, the panel area of ​​the LED package corresponding to the light intensity data is determined as the light intensity defect position.

6. The method for detecting LED package defects according to claim 4, wherein: In step S3, the panel of the LED package is powered on, and after power-on, the light intensity data of each position of the light intensity sensing panel is continuously obtained until the power-on time of the preset first light intensity is reached. The light intensity defect position of the LED package is determined based on the comparison result of the power-on time and the preset power-on time. If the power-on time is greater than the preset power-on time, the panel area of ​​the LED package corresponding to the time is determined as the light intensity defect position.

7. The method for detecting LED package defects according to claim 6, wherein: In step S4, the adjustment of the angle between the light intensity sensing panel and the LED package panel is determined based on the ratio of the area of ​​the LED package panel corresponding to the light intensity defect position to the total area of ​​the LED package panel, the light intensity data corresponding to each light intensity defect position and the concentration of each light intensity defect position.

8. The method for detecting LED package defects according to claim 7, wherein: In the step S5, the light intensity defect area of ​​the LED package is determined based on the comparison result of the light intensity data corresponding to each light intensity defect position after the angle adjustment and the preset second light intensity; If the light intensity data corresponding to each light intensity defect position after the angle adjustment is less than the preset second light intensity, the panel area of ​​the LED package corresponding to the light intensity data corresponding to each light intensity defect position after the angle adjustment is determined as the light intensity bad point area.

9. The method for detecting LED package defects according to claim 8, wherein: In step S6, the average light intensity data is the average light intensity of all light intensity data of the light intensity bad point area detected by the light intensity sensing panel after adjustment; based on the maximum gap and the preset maximum gap threshold, it is determined whether the area of ​​the light intensity bad point area is included in the bad point area, and the light intensity bad point area is calculated based on the bad point area.

10. The screening method for detecting LED package defects according to claim 9, characterized in that: In step S7, a defect screening value is calculated based on each of the maximum gaps, the area of ​​the light intensity bad spot, the angle adjustment value between the light intensity sensing panel and the panel of the LED package, the light intensity difference values ​​before the angle adjustment, the light intensity difference values ​​after the angle adjustment and the power-on time, and the LED package is screened according to the defect screening value.

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